1. Cross-Reference to Related Applications
Reference is made to commonly assigned, co-pending U.S. patent applications Ser. No. 751,912 entitled CHEMICAL ANALYZER, filed in the names of Louis C. Nosco, Anthony P. DiFulvio and Henry S. Adamski on Dec. 17, 1976, now abandoned; and Ser. No. 912,290 entitled ARTICLE DISPENSER APPARATUS, filed in the names of G. W. Scherer and R. G. Covington concurrently herewith.
2. Field of the Invention
The present invention relates to article containers from which individual articles can be sequentially removed from stacks of articles received in the containers.
3. Description of the Prior Art
In recent years, a number of automated systems have been developed for carrying out quantitative chemical analysis of fluid samples. While many of the commercially available systems utilize liquid reagents and require analyzer equipment having intricate solution handling and transport capabilities, one biological fluid analyzing apparatus in which discrete test slides containing individual dry reagents are metered through the apparatus to receive a drop of biological fluid to be tested is described in commonly assigned, co-pending U.S. patent application Ser. No. 751,912, entitled CHEMICAL ANALYZER filed on Dec. 17, 1976.
As described in that application, the test slides are stacked in containers, also called cartridges. A container may be received in a nest of the analyzing apparatus with a spring biased plunger arranged to enter the container through an opening. The plunger engages a movable element located in the container behind the slide stack to urge the slides forwardly toward a dispensing station at one end of the container. An example of such containers is disclosed in commonly assigned, copending U.S. patent application Ser. No. 912,290 entitled ARTICLE DISPENSER APPARATUS, filed in the names of G. W. Scherer and R. G. Covington concurrently herewith.
A push blade in the analyzing apparatus enters the container at the dispensing station to remove the leading slide from the container and move it into the analyzing apparatus by pushing it through a slot in the container wall. The remaining slides are sequentially moved forwardly in the container by the plunger as each preceding slide is removed.
The container has a substantially rectangular cross-sectional shape. As such, there is a distinct possibility that, in a busy hospital laboratory where numerous fluid samples are chemically analyzed daily, a container will occasionally be placed in its nest backwards. If unnoticed, such misorientation of the container may cause damage to the analyzer apparatus and would surely impose an unnecessary delay in the diagnosis process.
Each slide in a particular container has the same, appropriate reagent for a particular test, such as for example a reagent for testing glucose in blood serum. Other containers might house slides adapted for different tests. Unless the utmost care is exercised when a fresh cartridge is loaded into the analyzer nest, a container of slides with a reagent for one test may inadvertently be placed in the nest when slides for another test were in fact specified.